inorganic chemistry

If you laid out the periodic table on a table and asked, "What is the chemistry of every one of these boxes?", inorganic chemistry is the answer. It is the study of all the elements and the compounds they form — metals and their salts, the rocks and minerals of the Earth, the colours of stained glass, the rust on iron, the lithium in a battery, the platinum in a catalytic converter. Roughly speaking, it is everything except the vast family of carbon-and-hydrogen molecules that organic chemistry has carved out for itself.

More carefully: organic chemistry is the chemistry built on the carbon-hydrogen framework (chains and rings of carbon dressed in hydrogen), and inorganic chemistry is essentially all the rest of the periodic table. The boundary is a historical convenience, not a wall. Carbon shows up constantly in inorganic chemistry — in carbonates (CaCO3), in carbon monoxide and carbon dioxide, in metal carbides, in diamond and graphite, and in the huge field of organometallic compounds where a metal is bonded directly to carbon. Inorganic chemists care about how atoms are built, how they bond, what shapes molecules take, what colours and magnetism they show, and how electrons move in reactions.

The reason inorganic chemistry deserves its own large subject is that the elements behave in wildly different ways, and those differences are not random — they follow the logic of the periodic table. A common misconception is that "inorganic" means lifeless or unimportant. In fact life depends utterly on inorganic chemistry: the iron in your blood, the magnesium at the heart of chlorophyll, the calcium in your bones, the sodium and potassium that fire your nerves are all inorganic. This whole field rests on first understanding the atom and the periodic patterns that organise it.